DE10225607A1 - Method and device for the plasma treatment of workpieces - Google Patents

Abstract

The method and the device are used for the plasma treatment of workpieces. The workpiece is inserted into an at least partially evacuable chamber of a treatment station and the workpiece is positioned within the treatment station by a holding element. A connection of the chamber to at least one equipment supply is controlled by a valve block with at least two valves arranged in the vicinity of a chamber floor.

Description

The invention relates to a method for plasma treatment of workpieces in which the workpiece is at least in one partially evacuable plasma chamber Treatment station is used and in which the Workpiece within the treatment station of one Holding element is positioned.

The invention also relates to a device for Plasma treatment of workpieces that have at least one evacuable plasma chamber for receiving the workpieces and in which the plasma chamber in the area of a Treatment station is arranged, as well as at which the Plasma chamber from a chamber floor, a chamber lid and a lateral chamber wall is limited and at least one holding element for positioning the Has workpiece.

Such methods and devices are, for example used to make plastics with surface coatings Mistake. In particular, there are already such Methods and devices known to make inner or outer To coat surfaces of containers used for Packing of liquids are provided. About that devices for plasma sterilization are also known.

In PCT-WO 95/22413 a plasma chamber is used Inside coating of bottles made of PET described. The too coating bottles are made by a movable Floor lifted into a plasma chamber and in the area a bottle mouth with an adapter brought. Evacuation can occur through the adapter of the bottle interior. In addition, by a hollow lance into the interior of the adapter Bottles introduced to supply process gas. An ignition of the plasma is done using a microwave.

From this publication it is already known a plurality of plasma chambers on a rotating wheel to arrange. This will result in a high production rate of Bottles supported per unit of time.

In EP-OS 10 10 773 a feed device explained to evacuate a bottle interior and with To supply process gas. In PCT-WO 01/31680 a Plasma chamber described, in which the bottles of one movable lid that was previously introduced with a Mouth area of the bottles was connected.

PCT-WO 00/58631 also already shows the arrangement of plasma stations on a rotating wheel and describes a group for such an arrangement Assignment of vacuum pumps and plasma stations to one favorable evacuation of the chambers and the interior of the Support bottles. In addition, the Coating of several containers in one Plasma station or a common cavity mentioned.

Another arrangement for performing a Internal coating of bottles is described in PCT-WO 99/17334 described. In particular, an arrangement of a Microwave generator above the plasma chamber and a Vacuum and equipment supply through a bottom of the Plasma chamber described through.

In the vast majority of the known methods, container layers made of silicon oxides with the general chemical formula SiO _x are used to improve the barrier properties of the thermoplastic plastic material. In addition, portions of carbon, hydrogen and nitrogen can also be contained in the barrier layers produced in this way. Barrier layers of this type prevent oxygen from entering the packaged liquids and escape of carbon dioxide in the case of liquids containing CO ₂ .

The previously known methods and devices are still not adequate for one Mass production to be used in both low coating price per workpiece as well as a high one Production speed must be achieved.

The object of the present invention is therefore a To specify methods of the type mentioned in the introduction, that a supply of resources to the treatment station compact design, short process idle times and large Reliability is supported.

This object is achieved in that a Connection of the chamber to at least one Resource supply from one near one Valve block arranged at the chamber bottom with at least two Valves is controlled.

Another object of the present invention is a Device of the type mentioned in the introduction construct that a simple resource supply for Plasma chamber is supported with a compact structure.

This object is achieved in that in an area of the Chamber bottom a valve block with at least two valves to control a connection of the plasma chamber at least one equipment supply is arranged.

The arrangement of the valve block with the valves in the The area of the chamber floor becomes a very compact unit provided a spatially dense arrangement of several Plasma chambers supported side by side and the both the Assembly and subsequent service work made easier. In addition, the respective valves for Plasma chamber provided very short connecting channels, which lead to a shortening of process idle times because for example, the vacuum supply Connection channels must be evacuated, resulting in a corresponding time expenditure.

To support plasma treatment of workpieces it proves particularly advantageous that over at least one of the valves is controlled a negative pressure.

A quick evacuation process with compact constructive structure is supported in that at least two valves to connect at least two different vacuum levels can be used.

When coating hollow workpieces with their mouth are arranged downwards, it turns out as advantageous that an evacuation of a cavity of the Plasma station takes place through the chamber floor.

A simple technical implementation is also supported by that through the chamber floor Process gas is supplied.

A quick and even distribution of the process gas can be achieved in an interior of the workpiece be that the process gas through a lance in an interior of the workpiece is supplied.

A gradual reduction in pressure is supported that a first vacuum level via a primary vacuum valve is fed.

Deformation of the workpiece due to internal and external Differences in pressure are avoided in that a Interior of the workpiece and another interior of the Treatment station at least temporarily at the same time the vacuum supply can be connected.

To quickly achieve a relatively low Vacuum it proves advantageous that the Interior of the workpiece and the further interior of the Plasma chamber at least temporarily to one Vacuum supply with one compared to the first Vacuum supply connected to lower pressure become.

For carrying out an interior coating of Workpieces are proposed that the interior of the Workpiece for at least one for a longer period of time the vacuum supply is connected.

To enable easy opening of the Plasma chamber is provided that at least a portion the plasma chamber temporarily to one via the valve block Ambient pressure is connected.

A deformation of the workpieces due to too large Differences in pressure can be avoided in that at least a portion of the interior of the workpiece temporarily to an ambient pressure via the valve block is connected.

To support controllable ignition of the plasma it is proposed that in the area of the chamber lid of a microwave generator generated microwaves in the Cavity are initiated.

A typical application is that a workpiece is treated from a thermoplastic.

In particular, it is thought that an interior of the Workpiece is treated.

This makes it an extensive area of application concluded that a container is treated as a workpiece.

In particular, it is thought that as a workpiece a bottle of beverage is being treated.

A high production rate with great reliability and high product quality can be achieved in that the at least one plasma station from a rotating one Plasma wheel from input positioning to one Output positioning is transferred.

An increase in production capacity at only slightly increased equipment costs can be achieved by a plasma station multiple cavities are provided.

A simple process gas supply is supported that plasma gas of at least one predeterminable composition via at least one process gas valve with a Equipment supply is connected.

A typical application is defined as: Plasma treatment a plasma coating is carried out.

In particular, it is thought that the plasma treatment performed using a low pressure plasma becomes.

When coating plastic workpieces it proves advantageous that a Plasma polymerization is carried out.

A good surface adhesion is supported by the fact that through the plasma at least partially organic substances be deposited.

Particularly advantageous use properties This allows workpieces for packaging food be achieved by the plasma at least in part inorganic substances are separated.

When it comes to the treatment of packaging, this is particularly important thought that through the plasma a substance for Improvement of the barrier properties of the workpiece is deposited.

To support a high quality of use proposed that in addition an adhesion promoter to Improving adherence of the substance on one Surface of the workpiece is deposited.

High productivity can be supported that at least two workpieces in a common cavity be treated at the same time.

Another area of application is that as Plasma treatment performed a plasma sterilization becomes.

It is also contemplated that as a plasma treatment Surface activation of the workpiece is carried out. This makes a very compact design provided that the valve block in the vertical direction is arranged below the chamber floor.

A low height is supported by the fact that Valve block essentially next to the chamber base is arranged.

To ensure a simple constructive design and a simple assembly, it is possible that the Valve block with the chamber base is a common component formed.

This creates a controllable process gas supply supports that at least one of the process gas valves on one pointing downwards in the vertical direction Coupling element is connected.

In particular, it proves to be the case when a positionable lance as advantageous that the Coupling element as a connection to the lance carrying lance carriage is formed.

This results in a simple external geometry of the components supports that in the area of the lance slide Deflection channel for the plasma gas is arranged, which Plasma gas from the coupling element towards the lance passes.

One for different application requirements in adaptable controllability of the valves becomes simple provided that at least one of the valves designed as an electromagnetically controlled valve is.

Exemplary embodiments of the invention are shown in the drawings shown schematically. Show it:

Fig. 1 is a schematic diagram of a plurality of plasma chambers, which are arranged on a rotating plasma wheel and in which the plasma wheel is coupled to input and output wheels.

Fig. 2 shows an arrangement similar to Fig. 1, wherein the plasma station are each equipped with two plasma chambers,

Fig. 3 is a perspective view of a plasma wheel having a plurality of plasma chambers,

Fig. 4 is a perspective view of a plasma station with a cavity,

Fig. 5 is a front view of the device of FIG. 4 with a closed plasma chamber,

Fig. 6 shows a cross section according to section line VI-VI in Fig. 5,

Fig. 7 is a view corresponding to Fig. 5 with an open plasma chamber,

Fig. 8 is a vertical section according to section line VIII-VIII in Fig. 7,

Fig. 9 is an enlarged representation of the plasma chamber, to be coated bottle according to Fig. 6

Fig. 10 shows a further enlarged view of a connecting element for holding the workpiece in the plasma chamber,

Fig. 11 is a schematic representation of a positioning of a bottle-shaped workpiece within the plasma chamber using a pincer-like holding element,

A representation of a closed plasma chamber is disposed at the downstream of the chamber bottom, a valve block including a plurality of valves, Fig. 12,

Fig. 13 shows the arrangement of FIG. 12, after opening of the plasma chamber

Fig. 14 is an illustration of a comparison with FIG. 12 modified valve block,

Fig. 15 is a vertical section along section line XV-XV in Fig. 14 without showing pliers-like holding elements for the workpieces and

Fig. 16 is a horizontal section along section line XVI-XVI in Fig. 14 also without a pliers-like holding element shown.

From the illustration in FIG. 1, a plasma module (1) can be seen which is provided with a rotating plasma wheel (2). A plurality of plasma stations ( 3 ) are arranged along a circumference of the plasma wheel ( 2 ). The plasma stations ( 3 ) are provided with cavities ( 4 ) or plasma chambers ( 17 ) for receiving workpieces ( 5 ) to be treated.

The workpieces ( 5 ) to be treated are fed to the plasma module ( 1 ) in the area of an input ( 6 ) and forwarded via a separating wheel ( 7 ) to a transfer wheel ( 8 ) which is equipped with positionable support arms ( 9 ). The support arms ( 9 ) are arranged pivotably relative to a base ( 10 ) of the transfer wheel ( 8 ), so that a change in the distance of the workpieces ( 5 ) can be carried out relative to one another. As a result, the workpieces ( 5 ) are transferred from the transfer wheel ( 8 ) to an input wheel ( 11 ) with a greater distance between the workpieces ( 5 ) relative to one another relative to the separating wheel ( 7 ). The input wheel ( 11 ) transfers the workpieces ( 5 ) to be treated to the plasma wheel ( 2 ). After the treatment has been carried out, the treated workpieces ( 5 ) are removed from the area of the plasma wheel ( 2 ) by an output wheel ( 12 ) and transferred to the area of an output section ( 13 ).

In the embodiment according to FIG. 2, the plasma stations ( 3 ) are each equipped with two cavities ( 4 ) or plasma chambers ( 17 ). As a result, two workpieces ( 5 ) can be treated at the same time. Basically, it is possible to make the cavities ( 4 ) completely separate from one another, but in principle it is also possible to delimit only partial areas from one another in a common cavity space in such a way that an optimal coating of all workpieces ( 5 ) is ensured. In particular, it is contemplated here to separate the partial cavities from one another at least by means of separate microwave couplings.

Fig. 3 shows a perspective view of a plasma module ( 1 ) with a partially constructed plasma wheel ( 2 ).

The plasma stations ( 3 ) are arranged on a support ring ( 14 ) which is designed as part of a rotary connection and is mounted in the area of a machine base ( 15 ). The plasma stations ( 3 ) each have a station frame ( 16 ) which holds plasma chambers ( 17 ). The plasma chambers ( 17 ) have cylindrical chamber walls ( 18 ) and microwave generators ( 19 ).

A rotary distributor ( 20 ) is arranged in a center of the plasma wheel ( 2 ), via which the plasma stations ( 3 ) are supplied with operating resources and energy. Ring lines ( 21 ) can be used in particular for the distribution of operating resources.

The workpieces ( 5 ) to be treated are shown below the cylindrical chamber walls ( 18 ). Lower parts of the plasma chambers ( 17 ) are not shown for the sake of simplicity.

Fig. 4 shows a plasma station ( 3 ) in perspective. It can be seen that the station frame ( 16 ) is provided with guide rods ( 23 ) on which a carriage ( 24 ) for holding the cylindrical chamber wall ( 18 ) is guided. Fig. 4 shows the carriage ( 24 ) with the chamber wall ( 18 ) in a raised state, so that the workpiece ( 5 ) is released.

The microwave generator ( 19 ) is arranged in the upper region of the plasma station ( 3 ). The microwave generator ( 19 ) is connected via a deflection ( 25 ) and an adapter ( 26 ) to a coupling channel ( 27 ) which opens into the plasma chamber ( 17 ). In principle, the microwave generator ( 19 ) can be coupled both directly in the area of the chamber cover ( 31 ) and via a spacer element to the chamber cover ( 31 ) with a predeterminable distance to the chamber cover ( 31 ) and thus in a larger surrounding area of the chamber cover ( 31 ) , The adapter ( 26 ) has the function of a transition element and the coupling channel ( 27 ) is designed as a coaxial conductor. A quartz glass window is arranged in the region of a junction of the coupling channel ( 27 ) in the chamber cover ( 31 ). The deflection ( 25 ) is designed as a waveguide.

The workpiece ( 5 ) is positioned in the area of a sealing element ( 28 ) which is arranged in the area of a chamber base ( 29 ). The chamber base ( 29 ) is designed as part of a chamber base ( 30 ). To facilitate adjustment, it is possible to fix the chamber base ( 30 ) in the area of the guide rods ( 23 ). Another variant is to attach the chamber base ( 30 ) directly to the station frame ( 16 ). With such an arrangement, it is also possible, for example, to design the guide rods ( 23 ) in two parts in the vertical direction.

FIG. 5 shows a front view of the plasma station ( 3 ) according to FIG. 3 in a closed state of the plasma chamber ( 17 ). The carriage ( 24 ) with the cylindrical chamber wall ( 18 ) is lowered compared to the positioning in FIG. 4, so that the chamber wall ( 18 ) has moved against the chamber bottom ( 29 ). The plasma coating can be carried out in this positioning state.

FIG. 6 shows the arrangement according to FIG. 5 in a vertical sectional view. It can be seen in particular that the coupling channel ( 27 ) opens into a chamber cover ( 31 ) which has a laterally projecting flange ( 32 ). A seal ( 33 ) is arranged in the area of the flange ( 32 ) and is acted upon by an inner flange ( 34 ) of the chamber wall ( 18 ). In a lowered state of the chamber wall (18) therethrough, a seal is made of the chamber wall (18) relative to the chamber lid (31). A further seal ( 35 ) is arranged in a lower region of the chamber wall ( 18 ) in order to ensure a seal here also relative to the chamber bottom ( 29 ).

In the positioning shown in FIG. 6, the chamber wall ( 18 ) encloses the cavity ( 4 ), so that both an interior of the cavity ( 4 ) and an interior of the workpiece ( 5 ) can be evacuated. To support a supply of process gas, a hollow lance ( 36 ) is arranged in the area of the chamber base ( 30 ) and can be moved into the interior of the workpiece ( 5 ). The lance ( 36 ) is positioned by a lance slide ( 37 ) which can be positioned along the guide rods ( 23 ). A process gas channel ( 38 ) runs inside the lance slide ( 37 ) and, in the raised position shown in FIG. 6, is coupled to a gas connection ( 39 ) of the chamber base ( 30 ). This arrangement avoids hose-like connecting elements on the lance slide ( 37 ).

Fig. 7 and Fig. 8 show the arrangement of FIG. 5 and FIG 6 in a raised state of the chamber wall (18).. In this position of the chamber wall ( 18 ), it is possible to remove the treated workpiece ( 5 ) from the area of the plasma station ( 3 ) and to insert a new workpiece ( 5 ) to be treated. As an alternative to the positioning of the chamber wall ( 18 ) shown in the drawings in an open state of the plasma chamber ( 17 ) achieved by displacement upwards, it is also possible to carry out the opening process by displacing a structurally modified sleeve-shaped chamber wall downwards in the vertical direction.

In the exemplary embodiment shown, the coupling channel ( 27 ) has a cylindrical design and is arranged essentially coaxially with the chamber wall ( 18 ).

FIG. 9 shows the vertical section according to FIG. 6 in an enlarged partial illustration in the vicinity of the chamber wall ( 18 ). In particular, the overlap of the inner flange ( 34 ) of the chamber wall ( 18 ) over the collar ( 32 ) of the chamber cover ( 31 ) and the holding of the workpiece ( 5 ) by the holding element ( 28 ). In addition, it can be seen that the lance ( 36 ) is guided through a recess ( 40 ) in the holding element ( 28 ).

The positioning of the workpiece ( 5 ) in the area of the sealing element ( 28 ) can be seen in the enlarged illustration in FIG. 10. The sealing element ( 28 ) is inserted into a guide sleeve ( 41 ) which is provided with a spring chamber ( 42 ). A compression spring ( 43 ) is inserted into the spring chamber ( 42 ) and clamps an outer flange ( 44 ) of the sealing element ( 28 ) relative to the guide sleeve ( 41 ).

In the positioning shown in FIG. 10, a thrust plate ( 45 ) mounted on the lance ( 36 ) is guided against the outer flange ( 44 ) and presses the sealing element ( 28 ) into its upper end position. In this positioning, an interior of the workpiece ( 5 ) is insulated from the interior of the cavity ( 4 ). In a lowered state of the lance ( 36 ), the compression spring ( 43 ) displaces the sealing element ( 28 ) relative to the guide sleeve ( 41 ) in such a way that a connection between the interior of the workpiece ( 5 ) and the interior of the cavity ( 4 ) is created.

Fig. 11 shows the positioning of the workpiece ( 5 ) within the plasma chamber ( 17 ) with the aid of a holding element ( 46 ). The holding element ( 46 ) is designed like pliers and has two pivotably mounted holding arms ( 47 , 48 ). The holding arms ( 47 , 48 ) can be pivoted relative to axes of rotation ( 49 , 50 ). To ensure automatic fixation of the workpiece ( 5 ) by the holding element ( 46 ), the holding arms ( 47 , 48 ) are pressed by springs ( 51 , 52 ) into a respective holding position.

The holding element ( 46 ) is arranged above the chamber base ( 30 ), so that after lifting the chamber wall ( 18 ) there is lateral accessibility of the holding element ( 46 ). The workpiece ( 5 ) can thereby be transferred from a positioning element to the holding element ( 46 ) without a lifting movement of the workpiece ( 5 ) in the direction of a longitudinal axis ( 53 ) of the cavity.

Fig. 12 shows in detail a valve block ( 54 ) arranged below the chamber base ( 30 ). The valve block ( 54 ) consists essentially of a block housing which holds a plurality of valves ( 55 ). In particular, it is contemplated to use electromagnetically controlled valves ( 55 ).

In the exemplary embodiment according to FIG. 12, the valve block ( 54 ) is arranged directly below the chamber base ( 30 ). In principle, it is also conceivable to realize the chamber base ( 30 ) and the valve block ( 54 ) as a single component. The valves ( 55 ) are only shown schematically in FIG. 12. In particular, the valve block ( 54 ) according to the present embodiment has a primary vacuum valve ( 56 ) for supplying a first negative pressure stage and a secondary vacuum valve ( 57 ) for supplying a lower pressure than the first negative pressure stage. A process vacuum valve ( 58 ) is also arranged to maintain the vacuum in synchronism with the supply of the process gas. The process vacuum valve ( 58 ) avoids the transfer of extracted process gas into the supply circuits for the primary vacuum and the secondary vacuum.

A chamber vacuum valve ( 59 ) is used to support an optional or joint supply of negative pressure to the interior of the workpiece ( 5 ) and / or to the further interior of the plasma chamber ( 17 ), which performs a corresponding shut-off function. In particular, it is contemplated to supply the respective supply vacuum directly to the interior of the workpiece ( 5 ) via the valves ( 56 , 57 , 58 ) and to control the further interior of the plasma chamber ( 17 ) in a controlled manner via the chamber vacuum valve ( 59 ).

A workpiece vent valve ( 60 ) and a chamber vent valve ( 61 ) are used to support a predeterminable and mutually independent venting of both the interior of the workpiece ( 5 ) and the further interior of the plasma chamber ( 17 ).

A primary process gas valve ( 62 ) and a secondary process gas valve ( 63 ) are used to support the supply of different process gas compositions. Additional equipment ( 64 , 65 ) can be used to connect or derive additional equipment.

In the embodiment shown in FIG. 12, a plurality of valves are arranged one below the other in groups. Such an arrangement supports a connection of the valves to the corresponding resources. Such an arrangement also facilitates the electrical connection of electromagnetically controlled valves.

FIG. 13 shows the arrangement according to FIG. 12 after opening the plasma chamber ( 17 ) by lifting the chamber wall ( 18 ). In this operating state of the plasma station ( 3 ) all valves ( 55 ) are closed and the lance ( 36 ) is retracted into the chamber base ( 30 ) and the valve block ( 54 ) so that the workpiece ( 5 ) can be positioned laterally.

FIG. 14 shows an embodiment of the valve block ( 54 ) which is modified compared to FIG. 12 and FIG. 13. The embodiment shown here is particularly advantageous for supplying two plasma chambers ( 17 ) with a symmetrical design of the respective feed channels. The process gas valves (62, 63) are not shown in the illustrations of FIGS. 14 to Fig. 16.

The chamber vacuum valve ( 59 ), the workpiece ventilation valve ( 60 ) and the chamber ventilation valve ( 61 ) are arranged on an essentially identical vertical plane in a region of the valve block ( 54 ) facing the plasma chamber ( 17 ). The primary vacuum valve ( 56 ), the secondary vacuum valve ( 57 ) and the process vacuum valve ( 58 ) are arranged below this level and in the vertical direction.

Fig. 15 shows a further vertical sectional view that, for a triggering of the valves (55) control elements (69) are used respectively. The actuating elements ( 69 ) can be designed, for example, as electromagnetic coils which, depending on their respective electrical control, arrange the valves ( 55 ) in a closed position, an open position or, if appropriate, in intermediate positions. Within the valve block ( 54 ) runs a chamber connection channel ( 70 ) for a direct connection of at least one of the valves ( 55 ) to the interior of the plasma chamber ( 17 ) and a workpiece connection channel ( 71 ) for connecting at least one of the valves ( 55 ) to an interior of the workpiece to be treated ( 5 ).

Fig. 16 shows a connection of the valves ( 55 ). Flexible connecting lines ( 67 ) are plugged onto connecting pieces ( 66 ) and fixed with hose clips ( 68 ). The use of connecting pipes is also possible. The selection of suitable connecting lines ( 67 ) is made taking into account the design constraints.

A typical treatment process is explained below using the example of a coating process and carried out in such a way that the workpiece ( 5 ) is first transported to the plasma wheel ( 2 ) using the input wheel ( 11 ) and that the sleeve-like chamber wall ( 18 ) is inserted in a pushed-up state of the workpiece ( 5 ) into the plasma station ( 3 ). After the insertion process has been completed, the chamber wall ( 18 ) is lowered into its sealed position and, at the same time, both the cavity ( 4 ) and an interior of the workpiece ( 5 ) are evacuated at the same time.

After sufficient evacuation of the interior of the cavity ( 4 ), the lance ( 36 ) is inserted into the interior of the workpiece ( 5 ) and the sealing of the interior of the workpiece ( 5 ) from the interior of the workpiece ( 5 ) is sealed off by a displacement of the sealing element ( 28 ). 4 ) performed. It is also possible to move the lance ( 36 ) into the workpiece ( 5 ) synchronously with the beginning of the evacuation of the interior of the cavity. The pressure in the interior of the workpiece ( 5 ) is then further reduced. In addition, the positioning movement of the lance ( 36 ) is at least partially already carried out parallel to the positioning of the chamber wall ( 18 ). After reaching a sufficiently low vacuum, process gas is introduced into the interior of the workpiece ( 5 ) and the plasma is ignited with the aid of the microwave generator ( 19 ). In particular, it is intended to use the plasma to deposit both an adhesion promoter on an inner surface of the workpiece ( 5 ) and the actual barrier layer made of silicon oxides.

After the coating process has been completed, the lance ( 36 ) is removed from the interior of the workpiece ( 5 ) and the plasma chamber ( 17 ) and the interior of the workpiece ( 5 ) are ventilated. After reaching the ambient pressure within the cavity ( 4 ), the chamber wall ( 18 ) is raised again in order to remove the coated workpiece ( 5 ) and to enter a new workpiece ( 5 ) to be coated. To enable the workpiece ( 5 ) to be positioned laterally, the sealing element ( 28 ) is moved back into the chamber base ( 3 ) at least in some areas.

As an alternative to the described inner coating of workpieces ( 5 ), outer coatings, sterilizations or surface activations can also be carried out.

The chamber wall ( 18 ), the sealing element ( 28 ) and / or the lance ( 36 ) can be positioned using different drive units. In principle, the use of pneumatic drives and / or electrical drives, in particular in one embodiment as a linear motor, is conceivable. In particular, however, it is contemplated to implement curve control to support exact movement coordination by rotating the plasma wheel ( 2 ). The curve control can be carried out, for example, in such a way that control cams are arranged along a circumference of the plasma wheel ( 2 ), along which curve rollers are guided. The cam rollers are coupled to the components to be positioned.

The valves ( 55 ) are preferably actuated via a programmable electronic control. First, after closing the plasma chamber ( 17 ), the primary vacuum valve ( 56 ) is opened and the interior of the workpiece ( 5 ) and the interior of the plasma chamber ( 17 ) are evacuated at the same time. A pressure level in the range of 20 mbar to 50 mbar is reached. After the primary vacuum valve ( 56 ) has been closed, the secondary vacuum valve ( 57 ) is opened and the interior of the workpiece ( 5 ) and the interior of the plasma chamber ( 17 ) are first connected simultaneously to a vacuum source with a lower pressure level. After sufficient evacuation of the interior of the plasma chamber ( 17 ) surrounding the workpiece ( 5 ), the chamber vacuum valve ( 59 ) closes and only the interior of the workpiece ( 5 ) is evacuated further. A pressure level of approximately 0.1 mbar is reached.

After the chamber vacuum valve ( 59 ) has been closed and the lance ( 36 ) has generally already been positioned within the interior of the workpiece ( 5 ), the primary process gas valve ( 62 ) opens and a process gas of a first composition is supplied. For the process gas supply to the lance ( 36 ), the gas connections ( 39 ), for example shown in FIG. 6, in the region of the chamber base ( 30 ) are designed in such a way that a tubular coupling element is displaceably guided in a longitudinal direction within a bore-like recess. Sealing can be done using a dynamic ring seal. The tubular connecting element is carried by the lance slide ( 37 ) and establishes a connection to the plasma gas channel ( 38 ) within the lance slide ( 37 ). A corresponding displacement of the tubular connecting element within the bore-like recess ensures a connection to the process gas distribution for each positioning of the lance slide ( 37 ).

After a sufficient supply of process gas, the microwave generator ( 19 ) ignites the plasma in the interior of the workpiece ( 5 ). At a predetermined time, the primary process gas valve ( 62 ) closes and the secondary process gas valve ( 63 ) opens to supply a process gas of a second composition. At least temporarily, parallel to the opening of the process gas valves ( 62 , 63 ), the process vacuum valve ( 58 ) also opens in order to maintain a sufficiently low negative pressure in the interior of the workpiece ( 5 ). Here, a pressure level of approximately 0.3 mbar proves to be expedient.

After completion of the plasma coating, the workpiece vent valve ( 60 ) first opens and connects the interior of the workpiece ( 5 ) to an ambient pressure. With a predeterminable time delay after opening the workpiece ventilation valve ( 60 ), the chamber ventilation valve ( 61 ) also opens in order to raise the interior of the plasma chamber ( 17 ) completely to the ambient pressure again. After at least approximately reaching the ambient pressure within the plasma chamber ( 17 ), the plasma chamber ( 17 ) can open and the coated workpiece ( 5 ) is removed and replaced by a new workpiece ( 5 ) to be coated.

To remove any residues of the plasma treatment process within the workpiece ( 5 ), it is possible to introduce compressed air into the workpiece ( 5 ) before removing the workpiece ( 5 ) from the plasma chamber ( 17 ) and thereby to remove any impurities. The discharge of the compressed air can either take place in an environment of the plasma station ( 3 ), but in particular it is also contemplated to activate one of the negative pressure connections at the same time as the pressure is applied and thereby to carry out a defined suction of the contaminants. Alternatively, it is also contemplated to carry out the cleaning process exclusively by applying an additional vacuum and to carry out the cleaning process by inflowing ambient air.

In the case of a compressed air supply, in particular a supply through the lance ( 36 ) is envisaged, since this allows the purge air to be introduced into an area of the interior of the workpiece ( 5 ) which is arranged away from an opening of the workpiece ( 5 ). This supports a purging air flow in the direction of the opening of the workpiece ( 5 ) and an effective cleaning process is carried out.

Claims (58)

1. A method for plasma treatment of workpieces, in which the workpiece is used in an at least partially evacuable chamber of a treatment station and in which the workpiece is positioned within the treatment station by a holding element, characterized in that a connection of the chamber to at least one supply of operating fluid from one valve block ( 55 ) arranged in the vicinity of a chamber base ( 29 ) is controlled with at least two valves ( 56 ). 2. The method according to claim 1, characterized in that a vacuum is controlled via at least one of the valves ( 55 ). 3. The method according to claim 1 or 2, characterized in that at least two valves ( 55 ) are used to connect at least two different vacuum levels. 4. The method according to any one of claims 1 to 3, characterized in that an evacuation of a cavity ( 4 ) of the plasma station ( 3 ) through the chamber floor ( 29 ) takes place. 5. The method according to any one of claims 1 to 4, characterized in that process gas is supplied through the chamber bottom ( 29 ). 6. The method according to any one of claims 1 to 5, characterized in that the process gas is fed through a lance ( 36 ) into an interior of the workpiece ( 5 ). 7. The method according to any one of claims 1 to 6, characterized in that a first vacuum stage is supplied via a primary vacuum valve ( 56 ). 8. The method according to any one of claims 1 to 7, characterized in that an interior of the workpiece ( 5 ) and a further interior of the treatment station are connected at least temporarily at the same time to the vacuum supply. 9. The method according to any one of claims 1 to 8, characterized in that the interior of the workpiece ( 5 ) and the further interior of the plasma chamber ( 17 ) are connected at least temporarily at the same time to a vacuum supply with a lower pressure than the first vacuum supply. 10. The method according to any one of claims 1 to 9, characterized in that the interior of the workpiece ( 5 ) is connected to at least one of the vacuum supplies for a longer period of time. 11. The method according to any one of claims 1 to 10, characterized in that at least a portion of the plasma chamber ( 17 ) is temporarily connected to an ambient pressure via the valve block ( 54 ). 12. The method according to any one of claims 1 to 10, characterized in that at least a portion of the interior of the workpiece ( 5 ) is temporarily connected to an ambient pressure via the valve block ( 54 ). 13. The method according to any one of claims 1 to 12, characterized in that in the region of the chamber cover ( 31 ) from a microwave generator ( 19 ) microwaves are introduced into the cavity ( 4 ). 14. The method according to any one of claims 1 to 13, characterized in that a workpiece ( 5 ) is treated from a thermoplastic. 15. The method according to any one of claims 1 to 14, characterized in that an interior of a hollow workpiece ( 5 ) is treated. 16. The method according to any one of claims 1 to 15, characterized in that a container is treated as the workpiece ( 5 ). 17. The method according to any one of claims 1 to 16, characterized in that a beverage bottle is treated as the workpiece ( 5 ). 18. The method according to any one of claims 1 to 17, characterized in that the at least one plasma station ( 3 ) of a rotating plasma wheel ( 2 ) is transferred from an input position to an output position. 19. The method according to any one of claims 1 to 18, characterized in that a plurality of cavities ( 4 ) are provided by a plasma station ( 3 ). 20. The method according to any one of claims 1 to 19, characterized in that plasma gas of at least one predefinable composition via at least one process gas valve ( 62 , 63 ) is connected to an operating fluid supply. 21. The method according to any one of claims 1 to 20, characterized characterized in that as a plasma treatment Plasma coating is carried out. 22. The method according to any one of claims 1 to 21, characterized characterized in using the plasma treatment a low pressure plasma is carried out. 23. The method according to any one of claims 1 to 22, characterized characterized in that a plasma polymerization was carried out becomes. 24. The method according to any one of claims 1 to 23, characterized characterized in that at least in part by the plasma organic substances are separated. 25. The method according to any one of claims 1 to 23, characterized characterized in that at least in part by the plasma inorganic substances are separated. 26. The method according to any one of claims 1 to 25, characterized in that a substance for improving the barrier properties of the workpiece ( 5 ) is deposited by the plasma. 27. The method according to claim 26, characterized in that in addition an adhesion promoter for improving an adherence of the substance is deposited on a surface of the workpiece ( 5 ). 28. The method according to any one of claims 1 to 27, characterized in that at least two workpieces ( 5 ) are treated simultaneously in a common cavity. 29. The method according to any one of claims 1 to 20, characterized characterized in that as a plasma treatment Plasma sterilization is carried out. 30. The method according to any one of claims 1 to 20, characterized in that a surface activation of the workpiece ( 5 ) is carried out as a plasma treatment. 31.Device for the plasma treatment of workpieces, which has at least one evacuable plasma chamber for receiving the workpieces and in which the plasma chamber is arranged in the region of a treatment station, and in which the plasma chamber is delimited by a chamber base, a chamber cover and a lateral chamber wall and at least one Holding element for positioning the workpiece, characterized in that in a region of the chamber bottom ( 29 ) which faces away from the plasma chamber ( 17 ), a valve block ( 54 ) with at least two valves ( 56 ) for controlling a connection of the plasma chamber ( 17 ) to at least one Resource supply is arranged. 32. Apparatus according to claim 31, characterized in that at least one of the valves ( 55 ) is designed to connect negative pressure. 33. Apparatus according to claim 31 or 32, characterized in that the valve block ( 54 ) is designed to connect at least two different negative pressures. 34. Device according to one of claims 31 to 33, characterized in that for evacuating a cavity ( 4 ) of the plasma station ( 3 ) in the chamber bottom ( 29 ) at least one vacuum channel is arranged. 35. Device according to one of claims 31 to 34, characterized in that at least one channel for supplying process gas is arranged in the chamber bottom ( 29 ). 36. Device according to one of claims 31 to 35, characterized in that for the supply of process gas in an interior of the workpiece ( 5 ) into a lance ( 36 ) is arranged positionable relative to the chamber bottom ( 29 ). 37. Device according to one of claims 31 to 36, characterized in that the valve block ( 54 ) has a primary vacuum valve ( 56 ) for connecting a first negative pressure. 38. Apparatus according to claim 37, characterized in that the primary vacuum valve ( 56 ) at least temporarily connects both an interior of the workpiece ( 5 ) and a further interior of the plasma chamber ( 17 ) to a common vacuum supply. 39. Device according to one of claims 31 to 38, characterized in that the valve block ( 54 ) has a secondary vacuum valve ( 57 ) for connecting a lower vacuum relative to the first negative pressure. 40. Apparatus according to claim 39, characterized in that the secondary vacuum valve ( 57 ) connects at least temporarily only an interior of the workpiece ( 5 ) with the vacuum source. 41. Device according to one of claims 31 to 40, characterized in that the valve block ( 54 ) has a workpiece ventilation valve ( 60 ) for connecting an interior of the workpiece ( 5 ) with an ambient pressure. 42. Device according to one of claims 31 to 41, characterized in that the valve block ( 54 ) has a chamber ventilation valve ( 61 ) for connecting an interior of the plasma chamber ( 17 ) with an ambient pressure. 43. Device according to one of claims 31 to 42, characterized in that a microwave generator ( 19 ) is arranged in the region of the chamber cover ( 31 ). 44. Device according to one of claims 31 to 43, characterized in that the plasma station ( 3 ) for coating a workpiece ( 5 ) is made of a thermoplastic material. 45. Device according to one of claims 31 to 44, characterized in that the plasma station ( 3 ) is designed for coating a container-like workpiece ( 5 ). 46. Device according to one of claims 31 to 45, characterized in that the plasma station ( 3 ) is designed for coating an interior of a hollow workpiece ( 5 ). 47. Device according to one of claims 31 to 46, characterized in that the plasma station ( 3 ) for coating a workpiece ( 5 ) is designed in the form of a beverage bottle. 48. Device according to one of claims 31 to 47, characterized in that the at least one plasma station ( 3 ) is carried by a rotating plasma wheel ( 2 ). 49. Device according to one of claims 31 to 48, characterized in that a plurality of cavities ( 4 ) are arranged in the region of the plasma station ( 3 ). 50. Device according to one of claims 31 to 49, characterized in that one for providing at least two cavities ( 4 ) provided chamber wall ( 18 ) is arranged positionable. 51. Device according to one of claims 31 to 50, characterized in that the valve block ( 54 ) has at least one process gas valve ( 62 , 63 ). 52. Device according to one of claims 31 to 51, characterized in that the valve block ( 54 ) is arranged in the vertical direction below the chamber bottom ( 29 ). 53. Device according to one of claims 31 to 51, characterized in that the valve block ( 54 ) is arranged substantially next to the chamber base ( 30 ). 54. Device according to one of claims 31 to 51, characterized in that the valve block ( 54 ) with the chamber base ( 30 ) forms a common component. 55. Device according to one of claims 31 to 54, characterized in that at least one of the process gas valves ( 62 , 63 ) is connected to a coupling element pointing downwards in the vertical direction. 56. Apparatus according to claim 55, characterized in that the coupling element is designed as a connection to a lance carriage ( 37 ) carrying the lance ( 36 ). 57. Apparatus according to claim 55 or 56, characterized in that a deflection channel for the plasma gas is arranged in the region of the lance slide ( 37 ), which guides the plasma gas from the coupling element in the direction of the lance ( 36 ). 58. Device according to one of claims 31 to 57, characterized in that at least one of the valves ( 55 ) is designed as an electromagnetically controlled valve.